Maintaining sessions for seamless push-to-talk services

ABSTRACT

Embodiments include a system, method, and computer program product for providing seamless PTT services to a user. In an embodiment, a push-to-talk (PTT) component provides, to the user, PTT services with a talk group through connectivity to a data channel in a mobile network. A voice monitoring component monitors attributes of data connectivity on the data channel to determine when a voice quality falls below a threshold. When the voice quality is determined to fall below the threshold, a connectivity component requests the user to switch the connectivity to a voice channel. Then, the connectivity component dials a telephone number through the voice channel to access a voice conference bridge that provides the PTT services. To provide the PTT services, the voice conference bridge sets up a routing path to a session initiation protocol (SIP) session for the talk group, and routes voice communication through the SIP session.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Nonprovisional patentapplication Ser. No. 16/030,530, filed Jul. 9, 2018, entitled System andMethod for Seamless Push-To-Talk Services, which in turn claims priorityto U.S. Nonprovisional patent application Ser. No. 15/581,757, filedApr. 28, 2017, entitled Voice Connectivity of Push-to-Talk Clients,which claims benefit of U.S. Provisional Patent Application No.62/338,666, filed May 19, 2016, entitled Voice Connectivity ofPush-to-Talk Clients, all of which are incorporated herein by referencein their entireties.

BACKGROUND Field

Embodiments generally relate to providing Push-to-Talk (PTT) servicesthrough a PTT client operating on a device, and more particularly, toimproving the PTT client's voice connectivity.

Background

Two-way radio devices provide users access to PTT services, particularlyPTT voice communications. In a typical PTT voice communication system,such as a mobile radio system, the two-way radio devices enable users toexchange voice communications with others listening in. Those listeningor participating in the conversation may be referred to as a talk group.For a mobile radio system, the talk group may be those tuned to adesignated radio channel. In another example, a PTT talk group may be alogically defined voice communications group defined by a PTT user oroperator that allows users to send and receive voice messages from othermember users in the talk group. PTT voice communication systems areoften used by first responders and other security, public safety, andprivate user groups to facilitate immediate and efficient voicecommunications within a radio network's coverage area.

PTT voice communication systems also support half-duplex communicationmethods where only one member of a talk group can transmit and speak ata time, while the remaining members listen. When the transmit channel isreleased, other members may push to talk, e.g., key a radio, and seizecontrol of the transmitting function until the transmit function isreleased. To regulate who has the transmitting function, controlsignaling may be used to block other PTT users from transmitting. Thesignaling may be in- or out-of-band. In addition, voice activateddetection (VAD) may be used, preventing transmission when voice signalsare being received.

Client applications operating on mobile computing devices, such assmartphones, are available that provide PTT functionality among memberusers within a talk group. By providing PTT functionality, these clientapplications simulate the functionality of two-way radio devices. Toprovide the PTT functionality, these client applications utilize Voiceover IP (VOIP) or other digital voice technologies to transmit voicedata over data networks. Similar to radio-based PTT systems, IP-basedPTT clients may implement half-duplex or full duplex communications andmay control who is able to speak at any one time.

PTT clients operating on mobile computing devices, such as smartphones,typically provide PTT services using VoIP technology by connecting to amobile broadband data channel within a mobile data network, such as a 4Gnetwork. Although these mobile data networks are rapidly being built andexpanded, poor data coverage or degraded data coverage exists in manyparts of the country, particularly in remote or sparsely populatedlocations. Poor data connectivity renders ineffective many of thebenefits provided by the PTT clients. Particularly, poor dataconnectivity may degrade voice quality and render voice communicationbetween members of a talk group unintelligible.

BRIEF SUMMARY

What is needed are system, method, and computer program productembodiments, or combinations and sub-combinations thereof, to provideseamless Push-to-Talk (PTT) services to mobile devices regardless ofdata coverage in a mobile broadband data network. Embodiments includeimplementing a PTT client on the mobile device that switches between aconnectivity to a data channel or a voice channel depending on whethercurrent connectivity provides good voice quality.

In an embodiment to provide improved and seamless PTT connectivity to auser, a system implements a PTT component, a voice monitoring component,and a connectivity component. The PTT component provides to a user PTTservices with a talk group through connectivity to a data channel thataccesses a mobile network. Then, the voice monitoring component monitorsattributes of data connectivity on the data channel to determine when avoice quality falls below a threshold. When the voice quality isdetermined to fall below the threshold, the connectivity componentrequests the user to switch the connectivity from the data channel to avoice channel that accesses the mobile network. Upon receivingconfirmation from the user, the voice connectivity component dials atelephone number through the voice channel to access a voice conferencebridge that provides the PTT services.

In an embodiment to provide seamless PTT services by an agency system,the agency system implements a session setup component and a gatewaysetup component. The session setup component receives, through a mobilenetwork, a telephone call from a computing device operated by a user,and an associated automatic number identification (ANI) identifying thatuser. The telephone call is initiated by the computing device when thecomputing device determines that voice quality to a talk group, from aplurality of talk groups associated with the ANI, over a data channelfell below a threshold. Then, the session setup component requests amultimedia application server to retrieve the plurality of talk groupsbased on the received ANI. Based on instructions received from themultimedia application server, the gateway component sets up a routingpath to a session initiation protocol (SIP) session for each talk groupfrom the plurality of talk groups. To provide the user PTT services witheach talk group, the gateway component routes voice communicationsthrough a corresponding SIP session.

Further embodiments, features, and advantages, as well as the structureand operation of the various embodiments, are described in detail belowwith reference to accompanying drawings. It is noted that theembodiments are presented herein for illustrative purpose only.Additional embodiments will be apparent to persons skilled in therelevant art(s) based on the teachings contained herein.

BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES

The accompanying drawings are incorporated herein and constitute a partof this specification. In the drawings:

FIG. 1 is a block diagram illustrating a system for providing improvedPush-to-Talk (PTT) connectivity in a mobile network, according to anembodiment.

FIG. 2 is a block diagram illustrating a PTT client application,according to an embodiment.

FIG. 3 is a block diagram illustrating how an agency system provides PTTservices, according to an embodiment.

FIG. 4 is a flowchart illustrating a method for improving PTTconnectivity at a PTT client application, according to an embodiment.

FIG. 5 is a sequence diagram illustrating a process for improving PTTconnectivity at an agency system, according to an embodiment.

FIG. 6 is a diagram of an example computing system, according to anembodiment.

In the drawings, like reference numbers generally indicate identical orsimilar elements. Additionally, generally, the left-most digit(s) of areference number identifies the drawing in which the reference numberfirst appears.

DETAILED DESCRIPTION

As mentioned above, limited or unreliable data service may limitcapabilities of PTT client applications on a mobile device. To deal withthe limited or unreliable data service, embodiments monitor voicequality over the data channel to determine whether it degrades below athreshold. If the quality is degraded, embodiments provide an option toa user to dial in to a conference bridge over a voice channel. Afterdialing in, the conference bridge can support PTT over the voicechannel.

System

FIG. 1 is a block diagram illustrating a system 100 for providingimproved Push-to-Talk (PTT) connectivity in mobile network 103,according to an embodiment. As shown, system 100 includes mobile devices102, base stations 104, Internet Protocol (IP) network 106, publicswitched telephone network (PSTN) 108, agency system 110, and PTTworkstation 120. One or more of the devices, components, or systemsshown and subsequently described may be implemented on one or morecomputing devices using hardware, software, or a combination thereof.Such a computing device may include, but is not limited to, a devicehaving a processor and memory, including a non-transitory memory, forexecuting and storing instructions. The memory may tangibly embody thedata and program instructions. Software may include one or moreapplications and an operating system. Hardware may include, but is notlimited to, a processor, memory, and graphical user interface display.The computing device may also have multiple processors and multipleshared or separate memory components. For example, the computing devicemay be a part of or the entirety of a clustered computing environment.

Base stations 104, also referred to as base transceiver stations orradio base stations, provide users of mobile network 103 the ability toaccess one or more external networks such as IP network 106 or PSTN 108.Particularly, base stations 104 include telecommunications equipment tofacilitate wireless multimedia communications between user equipment,such as mobile devices 102, and the one or more networks. In anembodiment, IP network 106 is representative of a wired network,wireless network, or a combination thereof, and includes any combinationof local area networks (LANs), wide area networks (WANs), the Internet,or a radio-mobile network, etc. PSTN 108, sometimes referred to as theplain old telephone system (POTS), is representative of a collection ofinterconnected public telephone networks designed primarily for voicecommunications and related traffic. In an embodiment, PSTN 108 is acircuit-switched network in contrast to the packet-based network of IPnetwork 106. Circuit-switched networks have been traditionallyimplemented to provide consistent and persistent voice communications.

Base stations 104 each include transceiver equipment for supporting oneor more wireless data communication technologies and related networks,each of which is part of IP network 106. Such technologies and relatednetworks include, without limitation, 4G Long-Term Evolution (LTE), 3GCode Division Multiple Access (CDMA), Worldwide Interoperability forMicrowave Access (WiMAX), Wi-Fi, 3G Global System for Mobile (GSM),Enhanced Data (rates) for GSM Evolution (EDGE), High Speed Packet Access(HSPA) network, Universal Mobile Telecommunications System (UMTS), orother wireless wide area network (WAN) technologies.

Depending on the one or more types of wireless WAN technologiessupported, base stations 104 implement different channel interfaces,e.g., data channels or voice channels, for facilitating wirelesscommunications with mobile devices 102. Traditionally, wireless WANtechnologies, e.g., GSM or CDMA, implement voice channels, which only orprimarily service voice calls with very limited support and bandwidthfor text or short message service (SMS) transmission. Base stations 104traditionally route voice communications in voice channels through thecircuit-switched networks of PSTN 108. Some wireless WAN technologies,e.g., CDMA, may also implement data channels, which support multimediacommunications. Other wireless WAN technologies, e.g., 4G LTE may onlyimplement data channels. Multimedia communication within data channelsis routed through IP network 106.

As wireless WAN technologies have improved, data channels implementedby, e.g., 4G LTE technologies, have become reliable and fast enough tosupport persistent and high-quality voice data along with othermultimedia data. In fact, 4G LTE does not implement voice channels,rather all types of data, including voice data, are transmitted via datachannels. Moving voice data over the data channels and through datanetworks, such as IP network 106, enables more efficient use of thecellular spectrum since data channels are efficiently designed.Additionally, wireless technologies like 4G LTE improve voice quality byencoding voice data with High Definition (HD) audio codecs as voicepackets are sent through the data channels.

Base stations 104 are readily being updated with more advanced wirelessWAN technologies, e.g., 4G LTE, with support for efficient,high-bandwidth data networks However many base stations 104, such asthose in sparsely populated locations, are still utilizing legacywireless WAN technologies, e.g., GSM, that do not provide sufficient orany multimedia data coverage. For example, base station 104B may supportonly a legacy technology, such as GSM, that provides to mobile device102B voice communication over voice channel 138. Base station 104B mayroute voice communications to and from mobile device 102B with otherdevices via PSTN 108. In contrast, base station 104A may, for example,support CDMA, which may provide both voice channels 132-134 and datachannels 130-132 to mobile devices 102. But, as a user operating mobiledevice 102B moves further away from base station 104A, mobile device102B may lose data connectivity to base station 104A via data channel136. If this happens, mobile device 102B can only connect to mobilenetwork 103 through voice channel 138 provided by base station 104B.

In an embodiment, mobile devices 102 implements a PTT client applicationfor providing PTT services and improved voice connectivity to usersoperating respective mobile devices 102. To support PTT services andimproved voice connectivity, each of mobile devices 102 is a computingdevice having one or more network chips for communicating with basestations 104. Each of the network chips includes transceiver hardwarefor supporting one or more wireless WAN technologies. In an embodiment,voice communication provided by PTT services is provided via IP network106, a technology known as Voice over IP (VOW). As such, mobile devices102, such as mobile device 102A, provide PTT services and relatedfunctionality by connecting to IP network 106 via, for example, a Wi-Filink 131 or through data channel 130 provided by base station 104A. Byconnecting to IP network 106, mobile devices 102 not only communicatevoice data via VOIP, but also communicate video, text, files, or othermultimedia communication with other users accessing IP network 106 andwithin the same one or more talk groups in which users operating mobiledevices 102 belong. Although communicating multimedia content is useful,users often highly value voice communications because of its immediateand interactive nature.

In an embodiment to provide improved and persistent voice connectivity,the PTT client application on, for example, mobile device 102B, monitorsa quality of data received via, for example, data channel 136 toestimate or determine a quality of current voice communication betweenmember users of one or more talk group. If the voice quality falls belowan acceptable threshold level, the PTT client application requests theuser to connect to mobile network 103 via one of voice channels 132 or138. If the user confirms the switch to, for example, voice channel 132,the PTT client application dials a pre-programmed telephone number toagency system 110. Upon receiving the telephone call, agency system 110sets up voice communication paths between the calling device, mobiledevice 102B, and each talk group associated with the user operatingmobile device 102B. When data connectivity to a data channel improves,the PTT client application asks the user whether he or she would like toswitch back to data connectivity to access multimedia content, whichincludes voice communication among other types of content.

As discussed above, PTT services are particularly useful to users thatneed to facilitate immediate and efficient voice communications withinone or more PTT talk group. For example, PTT services supportfull-duplex or half-duplex communication functions where a user of atalk group may communicate with each member of that talk group byactivating a call, a button, or other voice transmission means. Users ofmobile devices 102 may be, for example, first responders and othersecurity, public safety, and private user groups.

Mobile devices 102 include, but are not limited to smartphones, laptops,tablets, or other portable devices. Each of mobile devices 102 includesan operating system that includes, but is not limited to, for example,the iOS platform produced by Apple Inc. of Cupertino, Calif., theAndroid platform produced by Google Inc. of Mountain View, Calif., theWindows platform produced by Microsoft Corp. of Redmond, Wash., theBlackberry platform produced by Blackberry Ltd. of Ontario, CA, or theopen-source Linux platform among other platforms. The operating systemof, e.g., mobile device 102A,runs the PTT client application downloadedon or implemented within mobile device 102A. The PTT client applicationis downloaded from, for example, agency system 110 via IP network 106.

Agency system 110 is a computer-based system that includes one or moreservers for providing PTT services to users associated with talk groupsmanaged by agency system 112. For example, for users that are policemen,emergency medical service (EMS) personnel, or construction workers,agency system 110 may represent a command center at a police station, anambulance service facility, or a construction office, respectively. Inan embodiment, agency system 110 is implemented partly or entirely in acloud-based computing environment, such as a private cloud, a governmentsecurity cloud, US army cloud, or an Amazon cloud, etc. To provide thePTT services, agency system 110 includes FW/VPN server 114, voiceconference bridge 116, and multimedia application server 118, each ofwhich is connected to local area network (LAN) 112. LAN 112 isimplemented as a wired network, a wireless network, or a combinationthereof.

FW/VPN server 114 includes one or more processors for establishingvirtual private network (VPN) tunnels or secure communication meansbetween computing devices, such as mobile devices 102 or workstation120, running respective PTT client applications. A VPN tunnel enablesdata, including PTT voice communications and multimedia content,communicated between PTT client applications and through IP network 106to remain encrypted, which increases privacy and security forcommunication between user members of a talk group. In an embodiment,FW/VPN server 114 provides end-to-end encryption using one or more ofhardware FPG-based or software-based encryption algorithms, such asAES256, as would be apparent to a person having ordinary skill in theart. In an embodiment, FW/VPN server 114 provides secure communicationmeans by encrypting data sent to and from FW/VPN server 114.

FW/VPN server 114 further includes firewall functions for monitoring andcontrolling incoming and outgoing network traffic to and from agency110. In an embodiment, firewall functions are implemented in a separatefirewall server coupled to FW/VPN server 114 or be implemented withinmultimedia application server 118.

Voice conference bridge 116 is implemented by one or more servers orprocessors to provide to mobile devices 102 PTT services over PSTN 108.In an embodiment, when one of mobile devices 102, such as mobile device102B, switches connectivity from a data channel to a voice channel, suchas voice channel 138, voice conference bridge 116 receives a telephonecall and an automatic number identification (ANI) identifying thecalling device, mobile device 102B. To provide PTT services over PSTN108, voice conference bridge 116 sends the ANI and a correspondingrequest to multimedia application server 118 to set up a voicecommunication session, such as a Session Initiation Protocol (SIP)session, for each talk group in which the user of mobile device 102Bbelongs. Multimedia application server 118 may not need to set up a newvoice communication session to a talk group if a session already exists.

In an embodiment, voice conference bridge 116 receives instructions orresults from multimedia application server 118. Based on the receivedinformation, for each talk group of the user, voice conference bridge116 sets up a routing path to a voice communication session to accessthat talk group. The voice communication session is an existing sessionor a newly created voice communication session. Voice conference bridge116 may further implement PTT functions to support, for example, PTTduplex-mode voice communications. By the process described above andfurther described with respect to FIGS. 3 and 5, voice conference bridge116 effectively maintains and manages a separate voice conference foreach talk group provided by agency system 110.

Multimedia application server 118 includes one or more processors tomanage talk groups provided by agency system 110. In an embodiment,multimedia application server 118 creates one or more talk groups andamends user memberships within each talk group. To manage membership oftalk groups, multimedia application server 118 includes a database tostore associations between users and talk group membership. The databasealso stores associations between a talk group and its current members.

In an embodiment, when multimedia application server 118 receives arequest for PTT communications from, for example, mobile device 102B viaIP network 106, multimedia application server 118 sets up a multimediacommunication session, such as a multimedia SIP session, between mobiledevice 102B and agency system 110. That multimedia communication sessionmay access one or more talk groups in which the user belongs and thatare managed by multimedia application server 118. If the multimediacommunication session was previously set up or configured, multimediaapplication server 118 directly routes PTT voice communications (andother multimedia content) between mobile device 102 and the requestedtalk group via the configured multimedia communication session.

In an embodiment, multimedia application server 118 also services PTTcommunication through a similar mechanism for devices, such asworkstation 120 or mobile device 102C, running respective PTT clientapplications and directly accessing LAN 112. Workstation 120 may be, forexample, a desktop computer used by an operator at agency system 110 tocommunicate with field personnel within one or more talk groups andoperating respective mobile devices 102. In an embodiment, mobile device102C represents an IP phone directly coupled to LAN 112 or a portablecomputing device accessing a Wi-Fi network (not shown) that is coupledto LAN 112.

In an embodiment, multimedia application server 118 provides PTTcommunications to mobile devices 102, such as mobile device 102B, overPSTN 108 via voice conference bridge 116 by setting up a voicecommunication session, such as a voice SIP session, for each talk groupin which the user is a member. In an embodiment, when a voicecommunication session has been previously configured for a talk group,multimedia application server 118 sends indication of that voicecommunication session to voice conference bridge 116 instead ofinstantiating a new voice communication session. Upon configuring orsetting up a voice communication session for a respective talk group,any PTT voice communication request from one or more mobile devices 102,operating over respective voice channels, is routed through that voicecommunication session.

In an embodiment, a third party system that interfaces with agencysystem 110 provides some or all of the agency system's PTT services andassociated functionality . For example, services provided by voiceconference bridge 116 may be implemented and provided by a third-party,such as an external PTT services vendor. To interface with an externalvoice conference bridge 116, agency system 110 implements a conferencebridge interface component within multimedia application server 118 oranother server. In an embodiment, the third-party vendor is a voiceservice provider (VSP), also known as an internet telephony serviceprovider (ITSP), that communicates voice data using VOIP. In otherwords, the VSP may communicate voice data with agency system 110 via IPnetwork 106.

FIG. 2 is a block diagram illustrating a PTT client application 202 forproviding seamless PTT communication and improving voice connectivity,according to an embodiment. In an embodiment, PTT client application 202is an exemplary implementation of a PTT client application downloaded onor implemented within one or more mobile devices 102 of FIG. 1 andworkstation 120 of FIG. 1. For ease of reference, the followingdescriptions will reference the devices and systems of FIG. 1.

In an embodiment, a computing device, such as one of mobile devices 102or workstation 120, includes one or more processors for implementingcomponents of PTT client application 202 to provide improved PTT voiceconnectivity and communications. For ease of understanding, descriptionsof the components of FIG. 2 may refer to FIG. 1. A component of PTTclient application 202 may include a selection of stored operations thatwhen executing in the one or more processors causes the one or moreprocessors to perform the operations of that component.

In an embodiment, to support improved voice connectivity, PTT clientapplication 202 implements the following components: user interface 203,voice monitoring component 204, PTT component 206, and connectivitycomponent 210. To support the operations of the components, PTT clientapplication 202 includes memory 220 for storing data connectivityattributes 222, voice quality 224, voice connectivity rules 226, andtalk group information 230.

User interface 203 enables a user operating PTT client application 202to access talk groups in which the user is a member. For example, userinterface 203 presents the user with PTT interface 303 on mobile device302A of FIG. 3. As shown, user interface 203 displays each of the user'stalk groups as talk group icons 304A-D, PTT buttons 305A-D coupled torespective talk group icons 304A-D, and the number of active members ofeach group. User interface 203 may also indicate which of the talkgroups are currently activated, e.g., receiving or transmitting voicecommunication, by highlighting or marking the associated talk group icon304. User interface 203 further detects whether one of PTT buttons 306is being selected. In an embodiment, detection depends on a type of thecomputing device operating PTT client application 202. For example, theselection may be detected on a touch on a touchscreen, a click by amouse, a sequence of characters entered via a keyboard, or other inputmeans.

In an embodiment, user interface 203 also prompts a user to switchbetween a connectivity to a voice channel or a data channel forproviding the PTT services. As shown in PTT interface 303, userinterface 203 shows current connectivity 308 as voice-only data, i.e.,connectivity provided via a voice channel. The prompting may beinitiated by connectivity component 210 when the voice channel providesbetter PTT voice connectivity than the data channel, as furtherdescribed below. In an embodiment, connectivity component 210 initiatesthe prompting when the PTT voice connectivity provided by the datachannel degrades below an acceptable threshold.

Voice monitoring component 204 monitors attributes of data connectivityon a data channel for communicating with agency system 110 to determinea voice quality, saved as voice quality 224 in memory 220. Similarly,the monitored attributes are saved as data connectivity attributes 222.In an embodiment, monitored data connectivity attributes 222 include oneor more of: a packet response time, a signal strength, a network speed,a packet loss rate, an available bandwidth, jitter, or a ping. In anembodiment, regardless of whether PTT client application 202 iscurrently providing PTT services via a voice channel or a data channel,voice monitoring component 204 continues to periodically monitor dataconnectivity attributes 222.

To determine voice quality 224, voice monitoring component 204 computesa value representing data connectivity quality based on one or more ofthe monitored or measured data connectivity attributes 222. Then, voicemonitoring component 204 uses the determined data connectivity qualityto compute voice quality 224 provided during the PTT voicecommunications. Voice quality 224 may be a score determined to estimatethe voice transmission's fidelity based on attributes 222. In anembodiment, voice monitoring component 204 additionally monitors ormeasures attributes of voice data received within the data channel tocompute voice quality 224. Attributes for voice data may include, forexample, jitter, response time, packet loss, echo, clock drift, orsynchronization measurements. These voice-specific attributes may alsobe stored as data connectivity attributes 222.

In an embodiment, voice quality 224 is determined based on whether acertain number of the monitored data connectivity attributes 222 are atan acceptable level, e.g., falling within a range of values. In anembodiment, if any of the monitored data connectivity attributes 222 isnot at or within an acceptable level, then voice monitoring component204 determines that voice quality 224 is poor. In another embodiment,voice quality 224 is computed as a function of data connectivityattributes 222. For example, if a monitored response time, an example ofone of data connectivity attributes 222, exceeds a pre-configuredthreshold, then regardless of the values of the other data connectivityattributes, voice communications may have significant delays renderingPTT voice services unintelligible. In an example, voice monitoringcomponent 204 may determine voice quality 224 is poor if PTT clientapplication 202 has disconnected from connectivity to the data channel,rendering voice connectivity nonexistent.

In an embodiment, voice monitoring component 204 concurrently monitorsnot only the attributes of data connectivity on an available datachannel, but also attributes for an available voice channel. Forexample, voice monitoring component 204 may monitor voice attributes ofvoice communications transmitted through a currently in-use voicechannel. At the same time, voice monitoring component 204 mayperiodically send or receive short messages, e.g., pings or IP packets,to an agency system over the data channel. Then, voice monitoringcomponent 204 computes or estimates respective voice qualities providedover the two separate channels. PTT client application 202, particularlyconnectivity component 210 described below, may use these computationsto determine whether to prompt the user, via user interface 203, toswitch to a connectivity channel that provides higher quality andpersistent PTT voice connectivity.

Connectivity component 210 interfaces with one or more network chips onthe mobile device, such as mobile device 102B, operating PTT clientapplication 202. In an embodiment, connectivity component 210 detects atleast a voice channel and at least a data channel provided by the one ormore network chips for accessing mobile network 103. Based on voicequality 224 computed by voice monitoring component 204, connectivitycomponent 210 determines whether to connect to one of the voice channelor the data channel for providing improved PTT voice connectivity. In anembodiment, upon determining that voice quality 224 is unacceptable on adata channel, connectivity component 204 requests the user to confirmswitching connectivity from the data channel to a voice channel foraccessing mobile network 103. This may be useful because voice quality224, which is computed from measured or monitored data connectivityattributes 222, does not necessarily correspond to a true voice quality.

In an embodiment, connectivity component 204 determines that voicequality 224 is poor or unacceptable if voice quality 224 falls below athreshold or is no longer within an acceptable range of values. To makethese comparisons, connectivity component 204 may query voiceconnectivity rules 226 for saved thresholds or range of values.

When switching connectivity from a data channel to a voice channel uponconfirmation from the user, connectivity component 210 automaticallydisconnects from the data channel and dials a telephone number over thevoice channel to access PTT voice connectivity. The telephone callroutes to voice conference bridge 116 identified by the telephonenumber. In an embodiment, the telephone number is preprogrammed withinmemory 220 or downloaded or received from agency system 110 thatprovides the PTT services. Upon dialing the telephone number andprocessing by voice conference bridge 116, connectivity component 210routes PTT voice communications over the telephone call on the voicechannel. In an embodiment, connectivity component 210 may switchconnectivity from the voice channel to the data channel and vice versawithout confirmation from the user.

In an embodiment, connectivity component 210 determines to switchconnectivity from the voice channel back to the data channel if voicequality 224 is high on the data channel, e.g., voice quality 224satisfies one or more thresholds or rules of voice connectivity rules226. In an embodiment, PTT voice connectivity over the data channel isbeneficial because the data channel enables users of PTT clientapplication 202 to communicate multimedia content, which includes moretypes of information than voice communication.

Similar to the embodiments described above, when switching from thevoice channel to the data channel, connectivity component 210 terminatesthe current telephone call over the voice channel to voice conferencebridge 116. Then, connectivity component 210 directly contacts agencysystem 110, particularly multimedia application server 118, over thedata channel to access the PTT services for each talk group in which theuser is a member. When connecting to multimedia application server 118,connectivity component 210 sends information identifying andauthenticating the user of PTT client application 202. Authenticationinformation may include one or more of the following: an InternetProtocol (IP) address, a media access control (MAC) address, a usernameand a password combination, or an email address. Multimedia applicationserver 118 uses this authentication information to set up PTT voiceconnectivity between the user of PTT client application 202 and theuser's talk groups managed or maintained by agency system 110.

PTT component 206 provides, to the user, the PTT services with each talkgroup in which the user belongs. When PTT client application 202 isaccessing the PTT services provided by agency system 100 via a datachannel, PTT component 206 directs voice communications and othermultimedia content to the selected talk group via IP network 106. Forexample, when the user selects a talk group icon, such as talk groupicon 306A from FIG. 3, to talk to other members of the talk grouprepresented by the talk group icon, PTT component 206 may send the voicecommunication to multimedia application server 118 for propagating toeach member of the talk group. PTT component 206 may concurrently send amessage, a sequence, or other identification information that specifiesthe selected talk group. In an embodiment, PTT component 206 searchesfor the specific talk group 232 stored in talk group information 230 tolocate talk group ID 234, representative of the information identifyingthe respective talk group 232.

In an embodiment, when PTT client application 202 is accessing the PTTservices provided by agency system 100 via a voice channel, PTTcomponent 206 mutes a microphone with respect to PTT client application202, mimicking the PTT functionality provided by traditional radiodevices. PTT component 206 may mute the microphone until at least a PTTbutton, such as PTT button 306A, of a respective talk group, such astalk group “PATROL” displayed in talk group icon 304A, is activated orselected by the user.

In an embodiment, when a PTT button is activated, e.g., selected by theuser, and detected by user interface 203, PTT component 206 searchestalk group information 230 for talk group 232 associated with theactivate PTT button. Based on talk group 232, PTT component 206 sendstalk group ID 234 associated with the searched talk group 232 to voiceconference bridge 116. In an embodiment, PTT component 206 looks up talkgroup 232 and associated talk group ID 234 in a separate table than whentransmitting multimedia communications to agency system 110 over a datachannel.

In an embodiment, by dialing into voice conference bridge 116, PTTcomponent 206 effectively provides PTT services via a conference call.Therefore, talk group ID 234 may be a dual tone multi frequency (DTMF)command, e.g., a sequence of dialed numbers transmitted to voiceconference bridge 116. But, other communication protocols and messagetypes can similarly identify talk group 232 and be transmitted over thevoice channel and PSTN 108.

In an embodiment, upon activating the PTT button, PTT component 206unmutes the talk group corresponding to the activated PTT button. Voicecommunications from the user may then be transmitted to each othermember of the talk group. In an embodiment, voice communications arecontinually sent over the voice channel to voice conference bridge. Uponactivating the PTT button, PTT component 206 sends an unmute controlalong with talk group ID 234 to voice conference bridge 116. Unmutecontrol may similarly be a DTMF command. Voice conference bridge 116then unmutes voice communications from PTT client application 202 withrespect to the talk group managed by agency system 110 and associatedwith the received talk group ID 234.

In an embodiment, when the user finishes speaking, she may deactivatethe PTT button, e.g., stop pressing or reselecting the PTT buttonprovided by user interface 203. Then, PTT component 206 may again mutePTT client application 202 with respect to the talk group coupled to thePTT button. In an embodiment where voice communications are continuallysent to voice conference bridge 206, PTT component 206 sends a mutecontrol to voice conference bridge 206. Much like the unmute controldescribed above, the mute control may be the same or a different DTMFcommand.

FIG. 3 is a block diagram of a system 300 that illustrates components ofan agency system 320 that provides PTT services, according to anembodiment. System 300 includes mobile devices 302, IP network 312, PSTN310, and agency system 320, each of which may correspond to thesimilarly named components of FIG. 1.

In an embodiment, PTT interface 303 depicts an example of user interface203 of FIG. 2 provided to mobile device 302A. For a user operatingmobile device 302A, PTT interface 303 displays one or more talk groupicons 304 representing each of the user's talk group. PTT interface 303also depicts PTT buttons 306 coupled to respective talk group icons 304.As described with respect to FIG. 2, the user may hold or select, forexample, PTT button 306A to speak to the members of the talk group“PATROL” identified by talk group icon 304A. PTT interface 303 mayadditionally depict the number of active members currently within talkgroup icons 304. Similarly, the user may release or re-select, forexample, PTT button 306A to deactivate PTT button 306A. Depending on thecurrent connectivity 308, e.g., via a voice channel or a data channel,as depicted within PTT interface 303, the PTT client application, suchas PTT client application 202, operating on mobile devices 302 providesthe PTT services via PSTN 310 or IP network 312, respectively.

In an embodiment, agency system 320 includes voice conference bridge321, LAN 326, and multimedia application server 340. Each of thesecomponents may correspond to the similarly named components of FIG. 1.

Multimedia application server 340 includes one or more processors tomanage talk groups provided by agency system 320. In an embodiment,multimedia application server 340 implements session managementcomponent 346, talk group configuration component 348, talk groupdatabase 350, and talk group component 342. A component multimediaapplication server 340 may include a selection of stored operations thatwhen executing in the one or more processors causes the one or moreprocessors to perform the operations of that component.

Talk group component 342 maintains or manages talk groups 344 providedby agency system 320. In an embodiment, talk group component 342 alsomaintains or manages real-time multimedia content communicated withineach of talk groups 344. Particularly, talk group component 342 enablesmember users within a talk group, such as talk group 344A, tocommunicate real-time multimedia communications for users communicatingover IP network 312 and voice-only communications for userscommunicating over PSTN 310.

Talk group configuration component 348 enables an administrator ofagency system 320 to create one or more talk groups and amend usermemberships within each of talk groups 344. In an embodiment, membershipmanagement capabilities are provided to a user operating a PTT clientapplication within mobile devices 302. To manage membership of talkgroups, multimedia application server 118 includes talk group database350 to store associations between users and their respective one or moretalk group memberships. Talk group database 350 may also store dataassociating each talk group, such as talk groups 344, and its currentmembers as well as active members. Each user can be identified in talkgroup database 350 based on one or more stored identificationinformation.

In an embodiment, user identification information includes an emailaddress or a username used to access a PTT client application operatingon, for example, mobile device 302A. Identification information may alsoinclude, for example, an IP address or a MAC associated with mobiledevice 302A. In the context of a telephone call made over PSTN 310, useridentification includes an automatic number identification (ANI)assigned to, for example, mobile device 302 and represents the caller'stelephone number, i.e., a telephone number of mobile device 302. Useridentification information can be used to authenticate users to providesecure PTT services. Additionally, talk group database 350 may storeauthentication information such as a username and a password combinationin order to authorize a user to access his one or more talk groups.

Session management component 346 sets up communication sessions withinLAN 326 for mobile devices 302 requesting access to one or more of talkgroups 344. In an embodiment, session management component 346 sets up amultimedia communication session, such as multimedia SIP session 330,for mobile device 302B requesting PTT services over IP network 312. Forexample, mobile device 302B may connect to IP network 312 via datachannel 130 from FIG. 1. Thus, multimedia SIP session 330 can connect auser operating mobile device 302B to the user's talk groups, such astalk group 344A. Similarly, session management component 346 sets up avoice communication session, such as voice SIP session 328, for mobiledevice 302A requesting PTT service to talk group 344A over PSTN 310. Forexample, mobile device 302A may connect to PSTN 310 via voice channel134 from FIG. 1.

SIP is a communication protocol commonly used in signaling andcontrolling multimedia sessions. Although SIP may be used to controlvoice and video calls, instant messaging, and other types of multimediacommunication, other types of communications protocols may be used bysession management component 346.

By maintaining multimedia SIP session 330 and, when needed, voice SIPsession 328A, talk group component 342 improves the connectivityprovided to each user communicating in, for example, talk group 344A.The flexibility of connecting to talk group 344A via IP network 312 orPSTN 310 further enables users' mobile devices 302 to pick the moststable and reliable connection such that each user maintains consistentconnectivity to his talk group, such as talk group 344A. Depending onbasestation locations, wireless technologies provided by nearbybasestations, wireless interference among other factors, the more stableand reliable connectivity type may vary from user to user. Thus, at anyinstance, some users, such as the user operating mobile device 302B, maybe connected to talk group 344A via multimedia SIP session 330, whileother users, such as the user operating mobile device 302A, may beconnected to talk group 344A via voice SIP session 328A.

In an embodiment, session management component 346 additionallyauthenticates a user requesting PTT services via mobile devices 302.Session management component 346 authenticates access by comparingreceived authentication or identification information with informationstored in talk group database 330. When multimedia application server340 receives a request for PTT communications from, for example, mobiledevice 302B via IP network 312, session management component 346 mayfirst authenticate that user.

Upon authenticating the user, session management component 346 looks upthe user, within talk group database 350, to identify one or more talkgroups 344 in which the user is a member. Then, session managementcomponent 346 may set up, for example, multimedia SIP session 330 foraccessing each of the user's talk groups. In the present example,multimedia SIP session 330 routes to talk group 344A. Upon setting upmultimedia SIP session 330, multimedia communications within talk group344A are routed to and from mobile device 302B via multimedia SIPsession 330.

In an embodiment, session management component 346 receives a requestfrom voice conference bridge 324 to set up voice communication sessionsto provide PTT services to, for example, mobile device 302A over PSTN310. In an embodiment, session management component 346 receives useridentification information, such as an ANI, from voice conference bridge321. Session management component 346 uses the received ANI to look upthe user in talk group database 340 and each of the user's talk groups.Then, session management component 346 sets up a corresponding voicecommunication session, such as voice SIP sessions 328, for each of theuser's talk groups. Session management component 346 may send the setupinstructions including the voice SIP sessions 328A-D back to voiceconference bridge 321.

In an embodiment, if multimedia SIP session 330 was previously set up orconfigured, session management component 346 may not need to re-create amultimedia communication session. In fact, the existing multimedia SIPsession 330 may enable direct multimedia communications between IPmobile device 302B and talk group 344A via LAN 326. Similarly, apreviously set up or configured voice communication session, such asvoice SIP session 328B, enables mobile device 302A to communicatedirectly with talk group 344B via LAN 326 and voice conference bridge321, as further described below.

In an embodiment, whenever a user terminates a telephone call, such as acall from mobile device 302A, session management component 346 receivesa corresponding termination notice or message from voice conferencebridge 321. Session management component 346 may further track thenumber of users sharing or using each voice communication session. In anembodiment, if no users are currently using a particular voicecommunication session, such as voice SIP session 328C, sessionmanagement component 346 terminates that voice communication session. Inan embodiment, the received termination notice itself indicates thatzero users are being routed through that specific voice communicationsession.

Voice conference bridge 321 is implemented by one or more servers toprovide PTT services over PSTN 310 to mobile device 302A and otherdevices dialing into voice conference bridge 321. In an embodiment,voice conference bridge 321 implements session setup component 322 andgateway component 324, each of which is implemented or executed by oneor more processors. A component multimedia application server 340 mayinclude a selection of stored operations that when executing in the oneor more processors causes the one or more processors to perform theoperations of that component.

Session setup component 322 provides the configuration steps that allowvoice communications from mobile device 302A over PSTN 310 to be routedto one or more of the user's talk groups 344 managed in multimediaapplication server 340. In an embodiment, when mobile device 302Aswitches connectivity from a data channel to a voice channel, voiceconference bridge 320 receives a telephone call from mobile device 302Aover PSTN 310. Voice conference bridge 320 may additionally receive anANI identifying the calling device, i.e., mobile device 302A.

To provide PTT services over PSTN 108, voice conference bridge 321 needsto route voice communications to the requested talk group. To do this,session setup component 322 sends a request, via LAN 326, to multimediaapplication server 340 to set up voice SIP sessions 328 that correspondto the user's talk groups. In an embodiment, the request includes useridentification information, such as ANI, that enables multimediaapplication server 340 to look up the talk groups in which the user is amember. Each member user of a talk group is assigned information thatidentifies that same talk group. Thus, to provide PTT services for eachmember, voice conference bridge 321 routes voice communications fromeach member to voice SIP sessions 328 that correspond to that same talkgroup.

In an embodiment, session setup component 322 itself maintains adatabase of users and their one or more talk groups. In this example,session setup component 322 may locate the talk groups of the user andsend a request to multimedia application server 340 to set up voice SIPsessions 328 that do not already exist.

In an embodiment, session setup component 322 receives instructions orresults from multimedia application server 118 regarding setup voice SIPsessions 328. Based on the received information, for each talk group ofthe user, session setup component 322 sets up and saves a routing pathto a voice communication session to access that talk group. The voicecommunication session may be an existing session or a newly createdvoice communication session. In an embodiment, one or more members of atalk group may share, for example, voice SIP session 328D, to access thecorresponding talk group 344D. As long as one or more member users(within the same talk group) are accessing or dialed into the voicecommunication session of voice SIP session 328D, session setup component322 continues to maintain voice SIP session 328D. A member user may dialinto voice SIP session 328D by operating, for example, his mobile device302.

Gateway component 324 implements PTT functions to support, for example,PTT half-duplex voice communications between a user, such as the useroperating mobile device 302A, dialing over PSTN 310 and other members ofthe user's one or more talk groups. To enable voice communications to besent between PSTN 310 and voice SIP sessions 328 over LAN 326, gatewaycomponent 324 performs gateway functions on the voice communications.

For example, when voice communications from another member of talk group344C is processed by talk groups component 342, gateway component 324may receive the voice communications via voice SIP session 328C. Gatewaycomponent 324 may further convert the voice communications for sendingto mobile device 302A over PSTN 310. Similarly, when gateway component324 transmits voice communications from PSTN 310 to talk groupscomponent 342, gateway component 324 may convert the voicecommunications for sending over LAN 326.

In an embodiment, gateway component 324 receives a PTT activationcommand from mobile device 302A over PSTN 310. The PTT activationcommand may be, for example, a DTMF command that indicates mobile device302A is requesting permission to transmit voice communications. In anembodiment, the PTT activation command includes an identification of aspecific talk group, such as talk group “TEAM 1” displayed in talk groupicon 304B. Gateway component 324 locates a specific routing path totransmit the user's voice communications to talk group 344B, whichcorresponds to the “TEAM 1.” The routing path may have been previouslyset up and saved by session setup component 322. Upon locating therouting path to voice SIP session 328B for connecting to talk group344B, gateway component 324 forwards voice communications from mobiledevice 302A to talk group 344B.

Method

FIG. 4 is a flowchart of a method 400 for providing improved PTTconnectivity with a PTT client application, according to an embodiment.The PTT client application connects to a mobile network, such as mobilenetwork 103 supported by basestations 104 from FIG. 1, to provide a userwith PTT services for a plurality of talk groups assigned or associatedwith that user. The user may operate the PTT client within a computingdevice, e.g., mobile device 102B from FIG. 1. Method 400 can beperformed by processing logic that may comprise hardware (e.g.,circuitry, dedicated logic, programmable logic, microcode, etc.),software (e.g., instructions running on a processing device), or acombination thereof.

In step 402, a PTT component within the PTT client application, such asPTT component 206 from FIG. 2, provides PTT services to the user byconnecting to a data channel, such as data channel 136 of FIG. 1, thataccesses the mobile network. The PTT component allows the user to usePTT services, such as PTT half-duplex communications, with each talkgroup in which the user belongs. The data channel further allows theuser to communicate multimedia data with other members in the user's oneor more talk groups.

In step 404, a voice monitoring component within the PTT clientapplication, such as voice monitoring component 204 of FIG. 2, monitorsor measures attributes of data connectivity on the data channel todetermine when a voice quality falls below a threshold. Additionally,the monitoring may be performed periodically or throughout the steps ofmethod 400.

In step 406, a connectivity component within the PTT client application,such as connectivity component 210 of FIG. 2, checks whether thedetermined voice quality is acceptable by comparing the computed qualityvalue with a predetermined or preconfigured threshold. If the voicequality is acceptable, method 400 proceeds to step 402 where PTTservices are maintained over the data channel.

In step 408, when the determined voice quality falls below thethreshold, the connectivity component requests the user to switch theconnectivity from the data channel to a voice channel, such as voicechannel 138 of FIG. 1, for accessing the mobile network. Althoughswitching to the voice channel from the data channel limits the typesmultimedia communications, the voice channel may provide more persistentvoice communications. In an embodiment, the connectivity componentdirectly switches to the voice channel without input from the useoperating the PTT client application.

In step 410, the connectivity component disconnects from the datachannel. In an embodiment, the connectivity component sends atermination request to end a current one or more multimedia SIPsessions, such as multimedia SIP session 330 of FIG. 3, forcommunicating with the user's one or more talk groups, such as talkgroup 344A of FIG. 3.

In step 412, the connectivity component dials a telephone number to avoice conference bridge, such as voice conference bridge 321 of FIG. 3,through a voice channel to provide the PTT services. Once the voiceconference bridge processes the telephone number, the voice conferencebridge provides the user access to each of the user's talk groups, suchas talk groups 344A-D, by routing voice communications through the voicechannel to and from voice communication sessions, such as voice SIPsessions 328A-D corresponding to respective talk groups 344A-D.

The telephone call may be routed to the voice conference bridge over aPSTN, such as PSTN 310 of FIG. 3. In an embodiment, the telephone numberis preprogrammed within PTT client application. In an embodiment, thePTT client application additionally updates the telephone number basedon updates received from agency system 320 or a third-party vendormaintaining or managing the voice conference bridge.

In step 414, the PTT component mutes a microphone of the PTT clientapplication to mimic PTT services, such as PTT half-duplex voicecommunications, provided by a traditional radio device.

In step 416, the connectivity component checks whether to switchconnectivity from the voice channel back to the data channel. Asdiscussed with respect to step 404, the voice monitoring component mayperiodically monitor data attributes of data connectivity on the datachannel to estimate or determine the voice quality. In an embodiment,when the voice quality is at an acceptable level, e.g., rises above apre-configured threshold, the connectivity component further enables theuser to switch to the data channel to access the PTT services andmultimedia communications with each talk group. If the user confirms,the connectivity component terminates the current connectivity to thevoice conference bridge via the voice channel. Then, method 400 proceedsto step 402. Otherwise, method 400 proceeds to step 418. In anembodiment, the connectivity component automatically switchesconnectivity to the data channel without user input or confirmation.

In step 418, the PTT component checks whether a PTT button correspondingto any talk group in which the user belongs has been activated. Forexample, the PTT component may detect that a virtual button, such as PTTbutton 306A of FIG. 3, within a screen of mobile device 302A has beenselected by the use operating mobile device 302A. The virtual button maybe selected via touch on touch screen, a computer mouse click, keyboardaccess, or other input means depending on the device operating the PTTclient application.

In step 420, if the PTT button for a talk group has been activated, thePTT component sends to the voice conference bridge informationidentifying the talk group coupled to the activated PTT button. In anembodiment, the identification (ID) information may be a DTMF command,e.g., a sequence of telephone numbers, associated with the PTT button.To enable PTT voice communication with the talk group, the PTT componentsends the DTMF command to the voice conference bridge via the voicechannel. To manage ID information for each talk group and associated PTTbutton, PTT client application maintains a table (or other storagemeans) of associations between talk groups and ID information. The voiceconference bridge processes the received ID information to route the PTTvoice communications between the user and the talk group identified bythe ID information.

In step 422, the PTT component unmutes the microphone of the PTT clientapplication with respect to the talk group activated by the PTT button.Upon unmuting, the user may transmit voice communications to each memberwithin the activated talk group so long as the PTT button continues tobe activated. As shown, method 400 proceeds to step 418 where if the PTTbutton is de-activated, e.g., selected or clicked again, method 400proceeds to step 414 where the PTT client is muted with respect to thetalk group coupled to the de-activated or de-selected PTT button.

FIG. 5 is a sequence diagram of a process 500 for improving PTTconnectivity at an agency system, particularly voice connectivity,according to an embodiment. Process 500 details how voice conferencebridge 504 and multimedia application server 506 together providesimproved PTT services and voice connectivity to a user operating PTTclient application 502 on a computing device or a mobile device, such asmobile device 302A of FIG. 3.

Components 502, 504, and 506 may be representative of PTT clientapplication 303, voice conference bridge 321, and multimedia applicationserver 340 from FIG. 3, respectively. Voice conference bridge 504 andmultimedia application server 506 may be managed or implemented by theagency system, such as agency system 320 of FIG. 3. In an embodiment,some or all of the functionality provided by the agency system, such asfunctionality of voice conference bridge 504, may be managed orimplemented by a third-party vendor that interfaces with the agencysystem. Process 500 can be performed by processing logic that maycomprise hardware (e.g., circuitry, dedicated logic, programmable logic,microcode, etc.), software (e.g., instructions run on a processingdevice), or a combination thereof.

For ease of understanding, steps of process 500 have been grouped intothe application functions 507, 515, 523, and 527. Application function507 provides PTT services to PTT client application 502 over a PSTN;application function 515 sends PTT voice communication from PTT clientapplication 502 over the PSTN; application function 523 sends PTT voicecommunication to PTT client application 502 over the PSTN; andapplication 527 switches connectivity from a voice channel to a datachannel to provide PTT services and voice communication to PTT clientapplication 502.

Application function 507 illustrates steps 508-514 for providing to PTTclient application 502 PTT services, including voice communication, overa PSTN, such as PSTN 310 of FIG. 3.

In step 508, voice conference bridge 504 receives a telephone call froma user's computing device operating PTT client application 502. In anembodiment, the telephone call is initiated by the computing device whenPTT client application 502 determines that voice quality to one of theuser's talk groups over a data channel fell below a threshold. In anembodiment, PTT client application 502 dials, via a voice channel, apreprogrammed telephone number routed to voice conference bridge via aPSTN, such as PSTN 310 of FIG. 3. In an embodiment, voice conferencebridge 504 additionally receives, from the PSTN, an ANI identifying theuser's computing device making the telephone call. The ANI may beassociated with one or more of the user's talk groups.

In step 510, voice conference bridge 504 requests multimedia applicationserver 506 to retrieve the plurality of talk groups in which the callinguser belongs, and set up a voice communication sessions for each talkgroup. In an embodiment, the request includes the received ANI that isused by multimedia application server 506 to identify the user and hismembership in specific talk groups.

Upon receiving the request, multimedia application server 506 queries adatabase or a table of ANI to locate talk groups associated with thereceived ANI. Then, multimedia application server 506 sets up respectivevoice communication sessions, such as voice SIP sessions 328A-D, for theuser's talk group icons 304A-304D. Each of the voice communicationsessions, e.g., voice SIP sessions 328A-D, provides PTT services andvoice connectivity to a corresponding talk group, e.g., correspondingtalk groups 344A-D.

In step 512, voice conference bridge 504 receives, from multimediaapplication server 506, instructions that indicate each of the user'stalk groups and respective voice communication sessions. In anembodiment, the instruction may be to connect to a newly created voicecommunication session or an existing voice communication session.

In step 514, for each of the user's talk groups, voice conference bridge504 sets up a routing path to a corresponding voice communicationsession such that PTT voice communications for that talk group arerouted through the voice communication session.

Application function 515 illustrates steps 516-522 for sending PTT voicecommunication from PTT client application 502 over the PSTN.

In step 516, voice conference bridge 504 receives, over the PSTN, a PTTactivation message or command from PTT client 502 to talk to members ofa talk group. In an embodiment, the PTT activation message is a DTMFcommand, e.g., a four-digit sequence of telephone numbers.

In step 518, voice conference bridge 504 receives voice communicationfrom PTT client application 502 over the PTSN. Upon receiving the voicecommunication, voice conference bridge 504 converts the voicecommunication into a packetized form for transmitting over the LAN orother IP networks to multimedia application server 506.

In step 520, voice conference bridge 504 uses the received PTTactivation command from step 516 to locate a voice communication sessionassociated with the talk group identified by the PTT activation command.For example, voice conference bridge 504 may perform a lookup operationon a table or database storing, for each user, PTT activation commandsand associated voice communication sessions.

In step 522, voice conference bridge 504 routes the converted voicecommunication from step 516 to the appropriate talk group via thelocated voice communication session of step 520.

Application function 523 illustrates steps 524-526 for sending PTT voicecommunication to PTT client application 502 over the PSTN.

In step 524, voice conference bridge 504 receives voice communicationsfrom a talk group, such as talk group 344A of FIG. 3, via acorresponding voice communication session, such as voice SIP session328A. The voice communication may be received as network packets andreceived over a LAN, such as LAN 326, if the agency system implementsthe voice conference bridge 504. Otherwise, voice conference bridge 504receives the voice communication via an IP network, such as IP network312. Upon receiving the voice communications, voice conference bridge504 performs gateway functions to convert the voice communication into aform suitable for transmitting over the PSTN and the voice channel, bothof which may maintain communications via a circuit-switched design.

In step 526, voice conference bridge 504 sends the converted voicecommunication over the PSTN to PTT client application 502. For example,voice communications from talk group 344A are sent to PTT clientapplication 303 as voice communication from talk group “PATROL”indicated by talk group icon 304A on PTT client application 303.

Application function 527 illustrates steps 528-538 for switchingconnectivity from a voice channel to a data channel to provide PTTservices and voice communication to PTT client application 502.

In step 528, multimedia application server 506 receives, over an IPnetwork, such as IP network 312 of FIG. 3, a request from PTT clientapplication 502 to access the user's talk groups.

In step 530, voice conference bridge 530 receives a request, over thePSTN, from PTT client application 502 to terminate the telephone callproviding the PTT voice connectivity to the user's talk groupsmaintained at multimedia application server 506. Upon receiving therequest, voice conference bridge 530 looks up the user's associated talkgroups based on received user ID, such as ANI.

In step 532, for each of the user's talk groups, voice conference bridge530 removes a route to a voice communication session for accessing thattalk group at the multimedia application server 506. In an embodiment,voice conference bridge 530 tracks whether one or more telephone callsfrom respective users are being routed through each active voicecommunication session.

In step 534, if a voice communication session no longer has any routedtelephone calls, i.e., the user requesting termination in step 530 wasthe only user accessing that voice communication session, then voiceconference bridge 530 requests multimedia application server 506 toterminate that voice communication session.

In step 536, voice conference bridge 530 receives results oracknowledgements from multimedia application server 506 and remove theidentified voice communication session of step 534 as an existing oractive voice communication session.

In step 538, responsive to step 528, multimedia application server 506establishes a multimedia communication session, such as multimedia SIPsession 330 of FIG. 3. In an embodiment, multimedia application server506 maintains the multimedia communication session to provide PTTservices, over IP network 312 of FIG. 3, to PTT client application 502using VOIP technology.

Computer System Implementation

Various embodiments can be implemented, for example, using one or morewell-known computer systems, such as computer system 600 shown in FIG.6. Computer system 600 can be any well-known computer capable ofperforming the functions described herein.

Computer system 600 includes one or more processors (also called centralprocessing units, or CPUs), such as a processor 604. Processor 604 isconnected to a communication infrastructure or bus 606.

One or more processors 604 may each be a graphics processing unit (GPU).In an embodiment, a GPU is a processor that is a specialized electroniccircuit designed to process mathematically intensive applications. TheGPU may have a parallel structure that is efficient for parallelprocessing of large blocks of data, such as mathematically intensivedata common to computer graphics applications, images, videos, etc.

Computer system 600 also includes user input/output device(s) 603, suchas monitors, keyboards, pointing devices, etc., that communicate withcommunication infrastructure 606 through user input/output interface(s)602.

Computer system 600 also includes a main or primary memory 608, such asrandom access memory (RAM). Main memory 608 may include one or morelevels of cache. Main memory 608 has stored therein control logic (i.e.,computer software) or data.

Computer system 600 may also include one or more secondary storagedevices or memory 610. Secondary memory 610 may include, for example, ahard disk drive 612 or a removable storage device or drive 614.Removable storage drive 614 may be a floppy disk drive, a magnetic tapedrive, a compact disk drive, an optical storage device, tape backupdevice, or any other storage device/drive.

Removable storage drive 614 may interact with a removable storage unit618. Removable storage unit 618 includes a computer usable or readablestorage device having stored thereon computer software (control logic)or data. Removable storage unit 618 may be a floppy disk, magnetic tape,compact disk, DVD, optical storage disk, and/any other computer datastorage device. Removable storage drive 614 reads from or writes toremovable storage unit 618 in a well-known manner.

According to an exemplary embodiment, secondary memory 610 may includeother means, instrumentalities or other approaches for allowing computerprograms or other instructions or data to be accessed by computer system600. Such means, instrumentalities or other approaches may include, forexample, a removable storage unit 622 and an interface 620. Examples ofthe removable storage unit 622 and the interface 620 may include aprogram cartridge and cartridge interface (such as that found in videogame devices), a removable memory chip (such as an EPROM or PROM) andassociated socket, a memory stick and USB port, a memory card andassociated memory card slot, or any other removable storage unit andassociated interface.

Computer system 600 may further include a communication or networkinterface 624. Communication interface 624 enables computer system 600to communicate and interact with any combination of remote devices,remote networks, remote entities, etc. (individually and collectivelyreferenced by reference number 628). For example, communicationinterface 624 may allow computer system 600 to communicate with remotedevices 628 over communications path 626, which may be wired orwireless, and which may include any combination of LANs, WANs, theInternet, etc. Control logic or data may be transmitted to and fromcomputer system 600 via communication path 626.

In an embodiment, a tangible apparatus or article of manufacturecomprising a tangible computer useable or readable medium having controllogic (software) stored thereon is also referred to herein as a computerprogram product or program storage device. This includes, but is notlimited to, computer system 600, main memory 608, secondary memory 610,and removable storage units 618 and 622, as well as tangible articles ofmanufacture embodying any combination of the foregoing. Such controllogic, when executed by one or more data processing devices (such ascomputer system 600), causes such data processing devices to operate asdescribed herein.

Based on the teachings contained in this disclosure, it will be apparentto persons skilled in the relevant art(s) how to make and useembodiments of the invention using data processing devices, computersystems or computer architectures other than that shown in FIG. 6. Inparticular, embodiments may operate with software, hardware, oroperating system implementations other than those described herein.

CONCLUSION

It is to be appreciated that the Detailed Description section, and notthe Summary and

Abstract sections (if any), is intended to be used to interpret theclaims. The Summary and Abstract sections (if any) may set forth one ormore but not all exemplary embodiments of the invention as contemplatedby the inventor(s), and thus, are not intended to limit the invention orthe appended claims in any way.

While the invention has been described herein with reference toexemplary embodiments for exemplary fields and applications, it shouldbe understood that the invention is not limited thereto. Otherembodiments and modifications thereto are possible, and are within thescope and spirit of the invention. For example, and without limiting thegenerality of this paragraph, embodiments are not limited to thesoftware, hardware, firmware, or entities illustrated in the figures ordescribed herein. Further, embodiments (whether or not explicitlydescribed herein) have significant utility to fields and applicationsbeyond the examples described herein.

Embodiments have been described herein with the aid of functionalbuilding blocks illustrating the implementation of specified functionsand relationships thereof. The boundaries of these functional buildingblocks have been arbitrarily defined herein for the convenience of thedescription. Alternate boundaries can be defined as long as thespecified functions and relationships (or equivalents thereof) areappropriately performed. Also, alternative embodiments may performfunctional blocks, steps, operations, methods, etc. using orderingsdifferent than those described herein.

References herein to “one embodiment,” “an embodiment,” “an exampleembodiment,” or similar phrases, indicate that the embodiment describedmay include a particular feature, structure, or characteristic, butevery embodiment may not necessarily include the particular feature,structure, or characteristic. Moreover, such phrases are not necessarilyreferring to the same embodiment. Further, when a particular feature,structure, or characteristic is described in connection with anembodiment, it would be within the knowledge of persons skilled in therelevant art(s) to incorporate such feature, structure, orcharacteristic into other embodiments whether or not explicitlymentioned or described herein.

The breadth and scope of the invention should not be limited by any ofthe above-described exemplary embodiments, but should be defined only inaccordance with the following claims and their equivalents.

What is claimed is:
 1. A system for a multimedia application server,comprising: a memory; one or more processors coupled to the memory,wherein the one or more processors are configured to: receive a requestfrom a voice conference bridge comprising an automatic numberidentification (ANI) identifying a computing device that supports a pushto talk (PTT) client application; determine a talk group associated withthe ANI; set up a voice communication session associated with the talkgroup, wherein a PTT voice communication associated with the talk groupis routed through the voice communication session via the voiceconference bridge; receive a request from a second PTT clientapplication to access the talk group; and responsive to the request fromthe second PTT client application, establish a multimedia communicationsession with the second PTT client application.
 2. The system of claim1, wherein the one or more processors are further configured to:transmit instructions that include the talk group and the voicecommunication session associated with the talk group to the voiceconference bridge; and receive a voice communication via the voicecommunication session associated with the talk group.
 3. The system ofclaim 2, wherein the voice communication is in a packetized form, andwherein the packetized form is received via an Internet Protocol (IP)network.
 4. The system of claim 1, wherein the one or more processorsare further configured to: receive a second voice communicationassociated with the talk group; and transmit the second voicecommunication via the voice communication session and the multimediacommunication session.
 5. The system of claim 1, wherein the one or moreprocessors are further configured to: receive a request from a videoconference bridge to terminate the voice communication sessionassociated with the talk group; and transmit a terminationacknowledgement to the video conference bridge.
 6. The system of claim1, wherein the one or more processors are further configured to:maintain the multimedia communication session to provide PTT servicesover the IP network using Voice over IP (VOIP) technology.
 7. The systemof claim 6, wherein the PTT services comprise half-duplex or full duplexcommunications.
 8. A method for a multimedia application server,comprising: receiving a request from a voice conference bridgecomprising an automatic number identification (ANI) identifying a pushto talk (PTT) client application; determining a talk group associatedwith the ANI; setting up a voice communication session associated withthe talk group, wherein a PTT voice communication associated with thetalk group is routed through the voice communication session; receivinga request from a second PTT client application to access the talk group;and responsive to receiving the request from the second PTT clientapplication, establishing a multimedia communication session with thesecond PTT client application.
 9. The method of claim 8, furthercomprising: transmitting instructions that include the talk group andthe voice communication session associated with the talk group to thevoice conference bridge; and receiving a voice communication via thevoice communication session associated with the talk group.
 10. Themethod of claim 9, wherein the voice communication is in a packetizedform, and wherein the packetized form is received via an InternetProtocol (IP) network.
 11. The method of claim 8, further comprising:receiving a second voice communication associated with the talk group;and transmitting the second voice communication via the voicecommunication session and the multimedia communication session.
 12. Themethod of claim 8, further comprising: receiving a request from a videoconference bridge to terminate the voice communication sessionassociated with the talk group; and transmitting a terminationacknowledgement to the video conference bridge.
 13. The method of claim8, further comprising: maintaining the multimedia communication sessionto provide PTT services over the IP network using Voice over IP (VOIP)technology.
 14. The method of claim 13, wherein the PTT servicescomprise half-duplex or full duplex communications.
 15. A non-transitorycomputer-readable medium storing instructions that, when executed by aprocessor of a first electronic device, cause the processor to performoperations, the operations comprising: receiving a request comprising anautomatic number identification (ANI) identifying a push to talk (PTT)client application; determining a talk group associated with the ANI;setting up a voice communication session associated with the talk groupwherein a PTT voice communication request from the PTT clientapplication is routed through the voice communication session; receivinga request from a second PTT client application to access the talk group;and responsive to receiving the request, establishing a multimediacommunication session with the second PTT client application.
 16. Thenon-transitory computer-readable medium of claim 15, further comprising:transmitting instructions that include the talk group and the voicecommunication session associated with the talk group to the voiceconference bridge; and receiving a voice communication via the voicecommunication session associated with the talk group.
 17. Thenon-transitory computer-readable medium of claim 15, further comprising:receiving a second voice communication associated with the talk group;and transmitting the second voice communication via the voicecommunication session and the multimedia communication session.
 18. Thenon-transitory computer-readable medium of claim 15, further comprising:receiving a request from a video conference bridge to terminate thevoice communication session associated with the talk group; andtransmitting a termination acknowledgement to the video conferencebridge.
 19. The non-transitory computer-readable medium of claim 15,further comprising: maintaining the multimedia communication session toprovide PTT services over the IP network using Voice over IP (VOIP)technology.
 20. The non-transitory computer-readable medium of claim 19,wherein the PTT services comprise half-duplex or full duplexcommunications.